JPH06148367A - Nuclear reactor - Google Patents

Abstract

PURPOSE:To contrive large enlargement of nuclear reactor output by equipping a plurality of reactor core vessels housing independent reactor cores in a nuclear reactor vessel and an intermediate cooler for heat-exchanging a primary coolant for a secondary coolant. CONSTITUTION:When a nuclear reactor is started, a primary coolant 26 is supplied to a reactor core vessel 31 through an inflow nozzle 36 from a high pressure plenum 29 in the lower part of a nuclear reactor vessel 25. Heating is performed due to nuclear reaction heat at the time when the coolant 26 passes reactor cores 35 in each vessel 31 and it is discharged from an outflow port 37 to an upper plenum 28. A primary coolant of high temperature guided to a plenum 28 is guided to an intermediate heat exchanger 45 from an inflow port 48 of an intermediate cooler 32 and passes through the tube bundle of the heat exchanger 45. At the time the primary coolant is heat-exchanged for the secondary coolant and cooled therewith. The secondary coolant heated with the exchanger 45 is transmitted to a steam generator 51 through an inflow and outflow tube 52 and feed water is heated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid metal cooling type nuclear reactor, and more particularly to a nuclear reactor provided with a plurality of core vessels each containing a module core in a nuclear reactor vessel.

[0002]

2. Description of the Related Art A liquid metal cooling type nuclear reactor is conventionally known as a fast breeder reactor. A typical configuration example of this fast breeder reactor is shown in FIG.

FIG. 6 is a vertical cross-sectional view showing a tank type reactor among liquid metal cooling type reactors. In this reactor, a reactor room 2 is surrounded by a biological shield wall 3 in a reactor building 1. And is formed on the building base mat 4 and the reactor room 2
A reactor vessel 5 as a primary coolant vessel is housed inside.

A liquid metal such as liquid metal sodium is filled as a primary coolant 6 in the reactor vessel 5, and a reactor core 7 is housed in the central portion of the reactor vessel 5. A large number of nuclear fuels are loaded in the core 7, and the inside of the reactor vessel 5 is divided into an upper plenum 8a and a lower plenum 8b with the core 7 as a boundary. The core 7 is supported on the reactor vessel 5 by a core support structure 9.

Above the core 7, there is provided an upper core mechanism 10 having a control rod driving device. This core upper mechanism 10
Is a shield plug 1 as an upper lid that covers the top of the reactor vessel 5.
While being supported by 1, the shield plug 11 has an intermediate heat exchanger 12 for exchanging heat between the primary coolant and the secondary coolant, and a circulation pump 13 for circulating the primary coolant in the reactor vessel 5.
Are provided around the core 7, respectively.

The intermediate heat exchanger 12 is connected to a steam generator 15 through a secondary coolant inflow / outflow pipe 14, and the steam generator 15 generates steam for driving a steam turbine (not shown). .

In this tank-type nuclear reactor, the primary coolant 6 heated by the nuclear reaction in the core 7 flows into the intermediate heat exchanger 12 from the upper plenum 8a when the nuclear reactor is started, and the intermediate heat exchanger 12 is heated. At 12, it is cooled by exchanging heat with the secondary coolant.

The primary coolant 6 cooled by the intermediate heat exchanger 12 is subsequently guided to the circulation pump 13 via the lower plenum 8b and is pressurized by the circulation pump 13. The pressurized primary coolant 6 is discharged to the high pressure plenum 8c below the core 7, and is guided to the core 7 again from this high pressure plenum 8c.

On the other hand, the secondary coolant heated by exchanging heat with the primary coolant 6 in the intermediate heat exchanger 12 is sent to the steam generator 15 through the outflow pipe of the inflow / outflow pipe 1, and this steam generator 15
The feed water is heated by this to generate steam for driving a steam turbine (not shown). The secondary coolant cooled by heat exchange in the steam generator 15 is returned to the intermediate heat exchanger 12 through the inflow / outflow pipe 14 to form a closed circulation loop of the secondary coolant.

[0010]

In the conventional liquid metal cooling type tank reactor, a single reactor core 7 is housed in the central portion of the reactor vessel 5, and the reactor core 7 has a reactor power output. It is becoming larger as it grows.

In the conventional liquid metal cooling type nuclear reactor, a single core is housed in the reactor vessel 5, and as the output of the reactor increases, the size of the single core is kept large. The control of the core becomes complicated, and if an abnormality occurs in a part of the core, it affects the behavior of the whole large core, so it is necessary to stop the nuclear reaction of the whole core.

Further, in the conventional nuclear reactor, since the single core 7 is kept to increase the size of the core, the core support structure 9 and other core structures become large and maintenance / maintenance of the core structure is improved. Large-scale removal / installation work is required for inspection / repair or replacement.

When the core support structure 9 is removed or installed, in addition to handling the core support structure 9 itself,
It is necessary to evacuate the entire reactor core to the outside of the reactor vessel 5, or to separately install a device for discharging and storing the liquid metal that is the primary coolant.

Further, in the conventional nuclear reactor, since the single core is kept and is enlarged, the output stop of the core 7 leads to the stop of the whole nuclear power plant, which is a heavy economical burden. Also, since the reactor core is single, it is necessary to carry out a core design and a nuclear criticality experiment each time according to the plant output of the nuclear power plant, which causes a problem that the verification cost of the core characteristics increases. .

The present invention has been made in consideration of the above-mentioned circumstances, and it is possible to increase the reactor output by combining a plurality of core vessels and to increase the reactor output. An object of the present invention is to provide a nuclear reactor capable of ensuring ease of core control.

Another object of the present invention is to improve the accessibility to the core vessel, simplify the removal and installation work of the core structure such as the core vessel, and easily and easily replace the core structure. It is to provide a reactor that can.

Still another object of the present invention is to provide a nuclear reactor capable of operating the output of a plant while partially stopping the operation of the core.

Another object of the present invention is to avoid a new core design and a nuclear criticality experiment even in a plant with a large single reactor output, and to significantly reduce the verification cost of core characteristics. To provide a furnace.

[0019]

In order to solve the above-mentioned problems, a nuclear reactor according to the present invention has a reactor vessel filled with a primary coolant as described in claim 1, and the above-mentioned nuclear reactor. A plurality of core vessels containing independent cores and an intercooler equipped with an intermediate heat exchanger for exchanging heat between the primary coolant and the secondary coolant are installed in the vessel.

Further, in order to solve the above-mentioned problems, the nuclear reactor according to the present invention is controlled in the core above each core vessel as described in claim 2 in addition to the contents of claim 1. Control rod drive devices for moving the rods in and out are respectively provided.

Further, in order to solve the above-mentioned problems,
A nuclear reactor according to the present invention has the following features.
A plurality of core vessels are installed in a row along the inner peripheral wall of the reactor vessel, and an intercooler is installed inside the annular zone on the core vessel side. A circulation pump for the primary coolant is provided below the intermediate heat exchanger for exchanging heat with the secondary coolant.

Further, in order to solve the above-mentioned problems, the reactor according to the present invention has a plurality of core vessels arranged inside along the inner peripheral wall of the reactor vessel as described in claim 4. In addition, the intermediate heat exchanger is installed inside the annular zone of the core vessel row, and the circulation pump for circulating the primary coolant is provided under each core vessel.

Further, in order to solve the above-mentioned problems, the nuclear reactor according to the present invention, as described in claim 5, has the upper opening of the nuclear reactor vessel closed by the upper lid, while A core vessel is detachably provided in the formed through-hole, and the number of core vessels installed in the reactor vessel can be freely selected.

[0024]

In the reactor according to the first aspect of the present invention, a plurality of core vessels containing the module cores are installed in the reactor vessel filled with the primary coolant. While the power output can be increased, the module core that is housed in each core container can be small, so it is possible to control a small core with simple nuclear characteristics and easy core operation control. become.

Further, in the nuclear reactor described in claim 2, a control rod driving device is provided above each core vessel, and the control rod driving device independently controls the operation of the core in each core vessel. Therefore, the plant output operation can be performed with the operation of the core partially stopped. On the contrary, even in a plant with a large output of a single reactor, partial shutdown operation of the core becomes possible.

Further, in the reactor according to the third aspect, since a plurality of core vessels are installed inside along the inner peripheral wall of the reactor vessel, the core vessels can be arranged in the periphery, and While the accessibility is improved, the intercooler arranged inside the annular zone of the core vessel row has an equipment configuration in which the intermediate heat exchanger and the circulation pump of the primary coolant are combined, so that A device arrangement space can be secured in the inner area.

Further, in the nuclear reactor described in claim 4,
Similar to the one described in claim 3, the accessibility to the core vessel is improved by arranging the core vessel in the periphery of the reactor vessel, while the core vessel is provided with a circulation pump for the primary coolant in the lower part of the core. Therefore, a sufficient installation space for the intermediate heat exchanger can be secured inside the annular band formed by the core vessel rows. Further, even if an abnormality occurs in the circulation pump, it is possible to continue the operation of the reactor without stopping the other module cores only by stopping the module core connected to the circulation pump in which the abnormality occurs. .

Furthermore, as described in claim 5,
By detachably providing the core vessel in the through hole formed in the upper lid that covers the upper opening of the reactor vessel, each core vessel can be inserted or removed through the through hole in the upper lid. Therefore, it is possible to replace the core structure of a plant having a large output of a single reactor by handling the small and lightweight core structure.

Further, selection of the number of core vessels and core operation
Depending on the combination, the required reactor power can be obtained.
At that time, all the core vessels can have the same core design, and the core design according to the plant output can be obtained by combining the single design cores, so that a new core design and a nuclear critical experiment are unnecessary, It is possible to significantly reduce the verification cost of core characteristics.

The module core accommodated in the core container is
A plurality of types may be prepared in advance and a plurality of types of core vessels may be combined.

[0031]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a nuclear reactor according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a liquid metal cooling type tank reactor. This reactor is
A reactor room 21 is formed in the reactor building 20. The reactor room 21 is formed on a building base mat 24 by being surrounded by a living body shielding wall 22 and a living body shielding ceiling wall 23 made of concrete, and a reactor vessel 25 as a tank type primary coolant container is stored inside. .

A liquid metal such as liquid metal sodium is filled as a primary coolant 26 in the reactor vessel 25, and is divided into an upper plenum 28 and a lower high pressure plenum 29 by a pressure partition wall 27 in the reactor vessel 25. .

The top opening of the reactor vessel 25 is covered with an upper lid 30 as a shielding plug, and a core vessel 31 and an intercooler 32 are vertically arranged at through holes formed in the upper lid 30. The upper lid 30 is a living body shielding ceiling wall 23
Part of the core vessel 31 and the intercooler 32.
Is hung vertically inside the vessel through the upper end plate of the reactor vessel 25.

A plurality of core vessels 31 are arranged inside along the inner peripheral wall of the reactor vessel 25, for example, 9 in a circumferential direction as shown in FIG. One (base) or a plurality of, for example, three intercoolers 32
Are placed.

Each core vessel 31 contains therein a core (module core) 35 composed of fuel rods and control rods, while an inflow nozzle 36 flows out at the lower end of the body of the core vessel 31 to the upper part of the body. Ports 37 are formed respectively. The inflow nozzle 36 engages with the attachment opening of the pressure partition 27 and opens into the lower high pressure plenum 29, and the outflow port 3
7 is open to the upper plenum 28.

A core shield plug 40 is attached to the upper opening of the core vessel 31, and a control rod drive device 41 is provided on the core shield plug 40. The control rod drive device 41 controls the movement of the control rod 42 into and out of the core 35. Further, the intercooler 32 includes a cylindrical intercooling container 44, and an intermediary heat exchanger 45 for exchanging heat between the primary cooling material and the secondary cooling material in the intercooling container 44 and a circulation pump for forcibly circulating the primary cooling material. And 46 are accommodated. The circulation pump 46 is composed of an electromagnetic pump,
It is installed below the intermediate heat exchanger 45.

An outlet nozzle 47 is provided below the circulation pump 46.
The outflow nozzle 47 is fitted and supported in the mounting opening of the pressure partition wall 27 and opens in the lower high pressure plenum 29. Further, the intermediate cooling container 44 is the intermediate heat exchanger 4
An inflow port 48 is formed above 5, and the inflow port 48 opens into the upper plenum 28.

An intercooler shield plug 50 is provided at the upper opening of the intercooler container 44.
A secondary coolant inflow / outflow pipe 52 connected to the steam generator 51 is provided at the upper part of 0. The inflow / outflow pipe 52 connects the steam generator 51 and the intermediate heat exchanger 45 to form a closed circulation loop for circulating the secondary coolant. The steam generator 51 is adapted to generate steam for driving a steam turbine (not shown).

When this reactor is started, the reactor vessel 2
The primary coolant 26 is supplied from the high pressure plenum 29 at the lower part of the No. 5 through the inflow nozzle 36 into the core vessel 31. The supplied primary coolant 26 is heated by nuclear reaction heat when passing through the core 35 in each core vessel 31, and is discharged from the outflow port 37 into the upper plenum 28.

The high temperature primary coolant guided to the upper plenum 28 is guided from the inflow port 48 of the intercooler 32 to the intermediate heat exchanger 45 and passes through the tube bundle of the intermediate heat exchanger 45. At that time, the primary coolant exchanges heat with the secondary coolant and is cooled. The primary coolant 26, which has been cooled by heating the secondary coolant, is pressurized by an electromagnetic pump, which is a circulation pump 46, and returned from the outflow nozzle 47 into the high pressure plenum 29.

On the other hand, the intermediate heat exchanger 45 of the intermediate cooler 32
The secondary coolant heated in (1) is sent to the steam generator 51 through the inflow / outflow pipe (outflow pipe) 52, where the feed water is heated and steam for driving a steam turbine (not shown) is obtained.

The secondary coolant cooled by heating the feed water is subsequently returned to the intermediate heat exchanger 45 of the intercooler 32 through the inflow / outflow pipe (inflow pipe) 52.

In this reactor, a plurality of core vessels 31 are housed in a reactor vessel 25 as a primary coolant vessel,
If the heat output per module core 35 formed in the core vessel 31 is, for example, a small core of 100,000 KW, nine core vessels 31 are provided in the reactor vessel 25 as shown in FIGS. 1 and 2. The thermal output of the contained reactor is 9 units × 100,000K
A large output of W = 900,000 KW (single unit reactor output) can be obtained. Therefore, unlike a conventional liquid metal cooling type reactor in which a single large reactor core is housed in a reactor vessel, a small reactor core combination that facilitates nuclear suppression is provided, and the characteristics of the small reactor core 35 are reduced. Taking advantage of this, a plant having a large output of a single reactor can be obtained, and the operation control of the core 35 can be easily performed.

For example, in the case of a small core having a heat output of 100,000 KW per core 35, the outer diameter of the core vessel 31 can be kept within 1.5 m.

Therefore, even if a plurality of core vessels 31 are accommodated in the reactor vessel 25 and the output of the single reactor is increased, the enlargement of the core support structure and other core structures can be avoided. Since it can be a small-sized core structure, it can be removed and replaced. Further, by disposing the core vessel 31 along the inner peripheral wall of the reactor vessel 25, accessibility to the core vessel 31 is improved. In particular, on the upper surface of the living body shielding ceiling wall 23, the accessibility of the fuel exchange device (not shown) to the individual module cores 35 and the accessibility for the removal and replacement of the core vessel 31 including the individual core support structures are improved. Improved and good.

Further, since the intercooler 32 arranged inside the annular band of the row of core vessels 31 has a device structure in which the intermediate heat exchanger 45 and the circulation pump 46 are combined, the inner region of the row of core vessels is formed. It is possible to secure a sufficient space for equipment placement.

FIGS. 3 and 4 show another embodiment of the nuclear reactor according to the present invention.

The nuclear reactor shown in this embodiment is different in the structure and the number of installed core vessels 60 and intercoolers 61 housed in the reactor vessel. Since it is not different from that shown in FIG. 2, common members are denoted by the same reference numerals, and description thereof will be omitted.

This reactor includes a plurality of reactors (groups) inside the reactor vessel 25 along the inner peripheral wall, for example, 10 reactor core vessels 6
0s are arranged in a row in the circumferential direction, and a core 62 is housed in the upper part of each core vessel 60, and a circulation pump 63, which is an electromagnetic pump, is housed in the lower part.

The core vessel 60 has an inflow nozzle 36 formed below the circulation pump 63, and the inflow nozzle 36 is fitted into and supported by an opening formed in the mounting portion of the pressure partition wall 27.
The inflow nozzle 36 communicates with the lower plenum 29.

In the core vessel 60, the outflow port 37 is formed above the core 62 and the pressure is increased by the circulation pump 63.
The primary coolant 26 heated by the core 62 flows out of the outflow port 37.
Through the upper plenum 28.

On the other hand, one or more (base) intermediate coolants 61 are arranged inside the annular band in which a plurality of core vessels 60 are arranged in a row in the circumferential direction. The intermediate cooler 61 is an intermediate heat exchanger 66 housed in a cylindrical intermediate cooling container 65. An outflow nozzle 47 is formed below the intermediate heat exchanger 66, and an inflow port 48 is formed above the intermediate heat exchanger 66. It

Therefore, the high temperature primary coolant 26 guided to the upper plenum 28 is transferred to the inflow port 4 of the intercooler 61.
8 is guided to an intermediate heat exchanger 66, and the intermediate heat exchanger 66 exchanges heat between the primary coolant 26 and the secondary coolant. Primary coolant 26 cooled by heating the secondary coolant
Is then discharged from the outflow nozzle 47 of the intercooler 61 into the lower plenum 29, and is again sucked into the inflow nozzle 36 of the core vessel 60 from the lower plenum 29.

On the other hand, the secondary coolant that has undergone heat exchange in the intermediate heat exchanger 66 and has risen in temperature is sent to the steam generator 51 through the inflow / outflow pipe 52, and the steam generator 51 heats the feed water to steam. It produces steam that drives a turbine (not shown). The secondary coolant whose temperature has been lowered by heating the feed water is returned again to the intermediate heat exchanger 66 through the inflow / outflow pipe 52 to form a closed secondary coolant circulation loop.

In this reactor, in addition to the effects obtained in the embodiment shown in FIGS. 1 and 2, the individual core vessels 61 are
When an abnormality occurs in the circulation pump 63 provided in the, the output of only the core 62 connected to this circulation pump 63 is stopped by the operation of the control rod drive device 41, and the corresponding circulation pump 6
By stopping only No. 3, it is not necessary to stop the other cores, and the plant operation can be continued as it is.

FIGS. 5 (A) and 5 (B) are plan views of the upper part of a nuclear reactor showing still another embodiment of the nuclear reactor according to the present invention.

FIGS. 5 (A) and 5 (B) show an example of changing the reactor output. In FIG.
The (core) core vessels 31 of the same design are accommodated, and in FIG. 5 (B), the six (core) core vessels 31 are accommodated.

Each core vessel 31 has the same core design, and for example, the heat output of one core (piece) is 10
If it is 10,000 KW, the reactor of FIG. 5 (A) can obtain a single-unit reactor output of 900,000 KW, and the reactor of FIG.
A single reactor power output of 10,000 KW can be obtained. Therefore, various reactor powers can be selected by combining the number of module cores that have been proved in the same core design.

In the description of the embodiments of the present invention, the core formed in the core vessel is the module small core which has been proved by the same core design, but the demonstration has plural kinds of heat output. A small core that has already been used may be prepared in advance.

[0061]

As described above, in the nuclear reactor according to the present invention, as described in claim 1, a plurality of core vessels accommodating the module cores are provided in the reactor vessel filled with the primary coolant. Since multiple units are installed, it is possible to increase the reactor output by combining multiple core vessels. On the other hand, the module core accommodated in each core vessel can be small, so Control of a small core with simple characteristics is sufficient, and core operation control becomes easy.

In the nuclear reactor according to the second aspect of the present invention, a control rod drive device is provided above each core vessel, and the operation control of the core in each core vessel is independently performed by this control rod drive device. Therefore, the plant output operation can be performed with the operation of the core partially stopped. On the contrary, even in a plant with a large output of a single reactor, partial shutdown operation of the core becomes possible.

On the other hand, in the reactor described in claim 3, since a plurality of core vessels are installed inside along the inner peripheral wall of the reactor vessel, the core vessels can be arranged in the periphery and While the accessibility is improved, the intercooler arranged inside the annular zone of the core vessel row has an equipment configuration in which the intermediate heat exchanger and the circulation pump of the primary coolant are combined, so that A device arrangement space can be secured in the inner area.

Further, in the nuclear reactor described in claim 4,
Similar to the one described in claim 3, accessibility to the core vessel is improved by arranging the core vessel in the periphery of the reactor vessel, while the core vessel is provided with a circulation pump for the primary coolant in the lower part of the core. Therefore, a sufficient installation space for the intermediate heat exchanger can be secured inside the annular band formed by the core vessel rows. Further, even if an abnormality occurs in the circulation pump, it is possible to continue the operation of the reactor without stopping the other module cores only by stopping the module core connected to the circulation pump in which the abnormality occurs. .

Furthermore, as described in claim 5,
By detachably providing the core vessel in the through hole formed in the upper lid that covers the upper opening of the reactor vessel, each core vessel can be inserted or removed through the through hole in the upper lid. Therefore, it is possible to replace the core structure of a plant having a large single-base reactor output by handling the small and lightweight core structure.

Further, selection of the number of core vessels and core operation
Depending on the combination, the required reactor power can be obtained.
At that time, all the core vessels can have the same core design, and the core design according to the plant output can be obtained by combining the single design cores, so that a new core design and a nuclear critical experiment are unnecessary, It is possible to significantly reduce the verification cost of core characteristics.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a nuclear reactor according to the present invention.

FIG. 2 is a plan view of the nuclear reactor shown in FIG.

FIG. 3 is a vertical sectional view showing another embodiment of the nuclear reactor according to the present invention.

FIG. 4 is a plan view of the nuclear reactor shown in FIG.

5 (A) and 5 (B) are plan views showing examples of changing the reactor output in the reactor according to the present invention.

FIG. 6 is a vertical cross-sectional view showing a conventional tank-type liquid metal cooling type nuclear reactor.

[Explanation of symbols]

 20 Reactor Building 21 Reactor Room 22 Living Shield Wall 23 Living Shield Ceiling Wall 24 Building Base Mat 25 Reactor Vessel (Primary Coolant Vessel) 26 Primary Coolant 27 Pressure Partition 28 Upper Plenum 29 Lower Plenum 30 Upper Lid 31,60 Core Container 32,61 Intercooler 35,62 Core 36 Inflow nozzle 37 Outflow port 40 Core shield plug 41 Control rod drive device 42 Control rod 45,66 Intermediate heat exchanger 46,63 Circulation pump (electromagnetic pump) 47 Outflow nozzle 48 Inflow Port 50 Intermediate coolant shielding plug 51 Steam generator 52 Inflow / outflow pipe

Claims (5)

[Claims] 1. A reactor vessel is filled with a primary coolant, and a plurality of core vessels accommodating independent cores in the reactor vessel and the primary coolant are heat-exchanged with a secondary coolant. A nuclear reactor characterized in that an intercooler equipped with an intermediary heat exchanger is installed respectively. 2. The nuclear reactor according to claim 1, further comprising a control rod driving device for moving control rods into and out of the core, which is provided above each core vessel. 3. A plurality of core vessels are installed in a row along the inner peripheral wall of the reactor vessel, and an intercooler is provided inside the annular zone on the core vessel side. A nuclear reactor characterized in that a circulation pump for the primary coolant is provided below an intermediate heat exchanger for exchanging heat between the primary coolant and the secondary coolant. 4. A plurality of core vessels are arranged in a row along the inner peripheral wall of the reactor vessel, and an intermediate heat exchanger is installed inside the annular zone of the core vessel row. A nuclear reactor characterized in that a circulation pump for circulating the primary coolant is provided at the bottom of the vessel. 5. An upper opening of the reactor vessel is closed by an upper lid, and a through hole formed in the shield plug is removably provided with the core vessel. Reactor characterized in that the number can be freely selected.